Amplitudes With Different Helicity Configurations Of Noncommutative QED

The amplitudes of purely photonic and photon{2-fermion processes of non- commutative QED (NCQED) are derived for different helicity configurations of photons. The basic ingredient is the NCQED counterpart of Yang-Mills recursion relations by means of Berends and Giele. The explicit solutions of recursion relations for NCQED photonic processes with special helicity configurations are presented.Comment: 23 pages, 2 figure

Fermions on an Interval: Quark and Lepton Masses without a Higgs

We consider fermions on an extra dimensional interval. We find the boundary conditions at the ends of the interval that are consistent with the variational principle, and explain which ones arise in various physical circumstances. We apply these results to higgsless models of electroweak symmetry breaking, where electroweak symmetry is not broken by a scalar vacuum expectation value, but rather by the boundary conditions of the gauge fields. We show that it is possible to find a set of boundary conditions for bulk fermions that would give a realistic fermion mass spectrum without the presence of a Higgs scalar, and present some sample fermion mass spectra for the standard model quarks and leptons as well as their resonances.Comment: LaTeX, 36 pages, 5 figure

INVERSE NEUTRINOLESS DOUBLE-BETA DECAY IN GAUGE THEORIES WITH CP VIOLATION

We investigate the reactions $e^-e^- \rightarrow W_i^-W_j^-$ for various gauge bosons production processes in the frame of the standard model with additional right-handed neutrinos and the Left-Right symmetric model. The present bounds on the various model parameters are taken into account. The question of the cross section behaviour for large energy and the CP violation problems are discussed.Comment: 21 pages,latex, figures not included (hard copy available on request

Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation

The current status of electric dipole moments of diamagnetic atoms which involves the synergy between atomic experiments and three different theoretical areas -- particle, nuclear and atomic is reviewed. Various models of particle physics that predict CP violation, which is necessary for the existence of such electric dipole moments, are presented. These include the standard model of particle physics and various extensions of it. Effective hadron level combined charge conjugation (C) and parity (P) symmetry violating interactions are derived taking into consideration different ways in which a nucleon interacts with other nucleons as well as with electrons. Nuclear structure calculations of the CP-odd nuclear Schiff moment are discussed using the shell model and other theoretical approaches. Results of the calculations of atomic electric dipole moments due to the interaction of the nuclear Schiff moment with the electrons and the P and time-reversal (T) symmetry violating tensor-pseudotensor electron-nucleus are elucidated using different relativistic many-body theories. The principles of the measurement of the electric dipole moments of diamagnetic atoms are outlined. Upper limits for the nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained combining the results of atomic experiments and relativistic many-body theories. The coefficients for the different sources of CP violation have been estimated at the elementary particle level for all the diamagnetic atoms of current experimental interest and their implications for physics beyond the standard model is discussed. Possible improvements of the current results of the measurements as well as quantum chromodynamics, nuclear and atomic calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for EPJ

The Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory is a second generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and epsf style files. For additional information about SNO see http://www.sno.phy.queensu.ca . This version has some new reference

Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

Peer reviewe

On the problem of patient specific endogenous glucose production in neonates on stochastic targeted (STAR) glycaemic control

Background: Stress and prematurity can both induce hyperglycaemia in the neonatal intensive care unit (NICU), which in turn is associated with worsened outcomes. Endogenous glucose production (EGP) is the formation of glucose by the body from substrates, and contributes to blood glucose (BG) levels. Due to the inherent fragility of the extremely low birth weight (ELBW) true fasting EGP cannot be explicitly determined, introducing uncertainty into glycaemic models that rely on quantifying glucose sources. STAR (Stochastic TARgeted) is one such glycaemic control framework. Methods: A literature review was carried out to gather metabolic and EGP values on preterm infants with a gestational age (GA) < 32 weeks and a birth weight (BW) < 2kg. The data was analysed for EGP trends with BW, GA, BG, plasma insulin and glucose infusion rates. Trends were modelled and compared to a literature-derived range of population constant EGP models using clinically validated virtual trials on retrospective clinical data. Results: No clear relationship was found for EGP and BW, GA, or plasma insulin. Some evidence of suppression of EGP with increasing glucose infusion or BG was seen. Virtual trial results showed that population constant EGP models fit clinical data best and gave tighter control performance to a target band in virtual trials. Conclusions: Variation in EGP cannot easily be quantified, and EGP is sufficiently modelled as a population constant in the NICING (Neonatal Intensive Care Insulin-Nutrition-Glucose) model. Analysis of the clinical data and fitting error suggests that ELBW hyperglycaemic preterm neonates have unsuppressed EGP in the higher range than that seen in literature

Nasogastric aspiration as an indicator for feed absorption in model-based glycaemic control in neonatal intensive care

STAR is a glycaemic control model-based framework for critically-ill neonates and has shown benefits in reducing hypo- and hyper- glycaemia. STAR uses a stochastic matrix method to forecast future changes in a patient’s insulin sensitivity, and then applies this result to a physiological model to select an optimal insulin treatment. Nasogastric aspiration may be used as an indicator to suggest periods of care when enteral feed absorption is compromised, improving the performance of glycaemic control. An analysis has been carried out to investigate the effect of poorly absorbed feeds on glycaemic control